偏高岭土对高性能水泥砂浆性能的影响

Effects of metakaolin on properties of high performance mortar

研究了偏高岭土的火山灰活性,考察了不同偏高岭土掺量对高性能水泥砂浆的流动度、抗折强度、抗压强度和氯离子渗透性的影响.试验结果表明:偏高岭土的火山灰活性高于硅灰;偏高岭土颗粒形貌的不规则性会降低新拌砂浆的流动度;偏高岭土的掺入使砂浆的抗折强度降低,90d养护龄期时偏高岭土掺量为10%的砂浆抗折强度高于偏高岭土掺量为6%,14%的砂浆抗折强度.偏高岭土掺量为10%的砂浆的后期抗压强度最高,90 d养护龄期时可达96.3 MPa;56 d龄期时偏高岭土掺量为0%,6%,10%,14%的砂浆的氯离子渗透性都较低,电通量分别为165,221,191,158 C.

The pozzolanic reactivity of metakaolin and the effects of different metakaolin contents on fluidity, flexural strength, compressive strength and chloride ion penetrability of high performance mortar are studied. The experimental results show that the pozzolanic reactivity of metakaolin is higher than that of silica fume. The irregular morphology of metakaolin decreases the fluidity of fresh mortars. The flexural strength of the mortars decreases due to the addition of metakaolin, and at the curing age of 90 d the flexural strength of the mortars with the metakaolin content of 10% is higher than those with the metakaolin contents of 6% and 14%. In addition, the compressive strength of the mortars with the metakaolin content of 10% is the highest, which reaches 96.3 MPa when the curing age is 90 d. The chloride ion penetrabilities of the mortars with the metakaolin contents of 0%, 6%, 10% and 14% are low when the curing age is 56 d, and the total charges are 165, 221, 191, 158 C, respectively.